The present invention relates to a knife-shield drive device and a method for the excavating and/or final supporting of galleries, tunnels, shafts or similar elongated structures, in which connection knives supported by support frames or guide arches are advanced one after the other and the support frames are moved further forward after the advance of all knives.
From Federal Republic of Germany No. OS 19 66 078 there is known such a device with drive knives which have guides which are rigid with respect to each other and are developed for rigid parallel guidance in the manner of the locks used in channel or sheet-piling. This device has the disadvantage that corrections in direction, which presuppose relative mobility of the individual drive knives with respect to each other, are not feasible or are feasible only with great difficulty. If in these known drive knives the lock clearance is increased, relative mobility of the knives with respect to each other is, it is true, obtained but on the other hand there is the disadvantage that the knives can move uncontrolled within the lock clearance so that precise control is not possible. There is also the disadvantage that upon the advance of the knives jamming frequently occurs in the rigid guides. This is true, in particular, if the knives come against stones in the face or wall and try to move out of their way.
From Federal Republic of Germany No. AS 27 42 332 a method is known in which drive knives which have lateral wedges are used. In that case the individual knives have relative mobility with respect to each other upon their advance, so that curves or corrections in direction can be handled. This known device has the disadvantage, however, that in order to obtain relative mobility for purposes of correction upon the advance all drive knives must always be driven forward in a given sequence, i.e., as a rule, commencing with the roof knife and then proceeding to the right and left of the latter. This structural sequence of the advance of the individual drive knives, which cannot be changed during the driving of the tunnel is disadvantageous if, for instance, in the case of rolling terrain knives must be driven forward in a different sequence in order to secure the breast wall.
In tunnel cross sections having, for instance, vertical side walls, the side knives move away as a result of the force of gravity in the direction towards the floor of the tunnel. This downward motion takes place, in particular, in the case of long and heavy knives, in connection with which the frictional forces between knife and earth, on the one hand, and between the guide arch and knife, on the other hand, are not sufficient to hold the knife in its position. Together with this, there are losses of ground as a result of gaping joints in the knife shield which are produced by the deviating of the knives. Furthermore, knives which have moved downward must be brought back into their old position in expensive manner by the aid of hydraulic presses.
Travel around a curve is very time and labor consuming. If a right-hand curve is to be moved over with the known method and the known apparatus then, to be sure, all knives lying to the right of the roof knife are steered in the desired direction by the action of the wedges applied to the knives but all knives lying to the left of the roof knife must be pushed individually in the desired direction in expensive fashion by, for instance, the aid of hydraulic presses.
From Federal Republic of Germany No. AS 20 21 734 there is known a traveling support scaffolding in which four support frames are connected, in each case, to two nested frame structures. This known arrangement is expensive because of the required frame structures and it requires very long knives with relatively small step. Long knives, however, in addition to a higher expense mean, in particular, a more difficult manipulability upon travel around curves and changes in direction.
From Federal Republic of Germany No. OS 26 18 571 there is known a self-supporting support unit formed of knife boards for small gallery cross sections. The knife boards are guided there at all times rigidly on each other via dovetail-like guides so that changes in direction which presuppose relative mobility of the knives with respect to each other cannot take place. Furthermore, in order to produce a closed ring, knife boards are also arranged on the floor of the tunnel, which greatly impairs the handiness of this known device.